Floppy diskettes or disks onto which information has been entered for later access or retrieval by a computer's magnetic transducer are customarily used and stored in diskette or disk jackets or cartridges. Such jackets are usually lined with porous, low-friction materials, preferably ones having antistatic properties, which protect the magnetic recording surface of the diskette or disk from damage and contamination from dust and other particulate matter during storage, handling and use. Such liners also clean contaminants that may be present from the magnetic recording surface of the diskette or disk while its stored information is being accessed by the computer.
Nonwoven fabrics whose fiber content has been bonded by heat to fuse individual fibers together at their crossover points, and nonwovens bonded by applying a liquid adhesive substance, e.g., a natural or synthetic polymer latex or emulsion, to a fibrous mat or web, including such nonwovens onto or into which an antistatic agent has also been incorporated, have been disclosed as being useful as diskette or disk jacket or cartridge liners.
Included among prior art disclosures of diskette or disk jacket or cartridge liners are those found in the following sources:
U.S. Pat. No. 3,668,658, issued June 6, 1972 to Flores et al, discloses diskette jackets or cartridges having inner layers which comprise "a porous, low-friction, antistatic material" which is not, however, a pre-formed nonwoven fabric; see, e.g., from column 2, line 72 to column 3, line 17.
U.S. Pat. No. 3,931,644,issued Jan. 6, 1976 to Ward, discloses a diskette or disk jacket or cartridge lined with "disk-engaging liners . . . of suitable, static-free material"; column 3, lines 30-36.
U.S. Pat. No. 3,864,755, issued Feb. 4, 1975 to Hargis, discloses a particular construction for a diskette jacket or cartridge liner which incorporates "wiper layers made of a non-woven synthetic fiber [which] . . . provide low friction, antistatic surfaces"; see, e.g., column 2, lines 2-5. The wiper layers are disclosed as being "made of a porous, low-friction, anti-static material"; see column 2, lines 63 and 64, which is "a synthetic and non-woven fibrous material", column 3, lines 36-44.
U.S. Pat. Nos. 4,586,606 and 4,610,352, issued May 6 and Sept. 9, 1986 Howey and Howey et al, respectively, disclose particular thermally bonded nonwoven fabric constructions used as diskette jacket or cartridge liners; see, e.g., column 1, lines 5-9 and 25-43; column 2, lines 55-65; column 5, lines 6-9 and column 7, lines 7-24 of the '606 patent.
U.S. Pat. No. 4,251,843, issued Feb. 17, 1981 to Masuyama et al, discloses an improvement in:
"(t)he conventional disc jacket . . . provided on the inner surface thereof with a fibrous layer made of nonwoven cloth or the like for protecting and cleaning the surface of the disc", PA1 " . . . made [of] fibrous materials such as nylon (polyamide), polyesters, viscose rayon, cellulose acetate, polypropylene, acrylic resins, alkyl acrylate copolymers and so forth mixed with a binder to form [a] nonwoven cloth. The nonwoven materials are fabric-like products which are made by arranging fibers (the above-[described] fibrous materials), in a web or mat form by a conventional method and then bonding the fibers to each other using an adhesive such as a natural latex, e.g., a latex of natural rubber, a synthetic latex or such in combination with urea resins or melamine [resin adhesives], or by utilizing the adhesive force of the fibers themselves, e.g., when using polyethylenes, polypropylene or polyamides. Of the synthetic [latices], acrylonitrile-butadiene copolymers and acrylonitrile are preferred, with synthetic [latices] of a molecular weight of about 800 to about 10,000 being most preferred", PA1 "Currently the porous fibrous, low-friction, anti-static liner material is fabricated by bonding together a loose mass of synthetic fibers. Within the category of materials fabricated in the foregoing manner, there are two materials made from different compositions of fibers and formed into a whole mass in different ways, currently in wide use as floppy disk liner materials. The first kind includes a mixture of 70% to 80% rayon fibers with 30% to 20% polypropylene fibers. The polypropylene fibers have a lower softening temperature than the rayon fibers. Thus, a loose mixture of these fibers is normally bound into a cohesive layer by heating such a mass of fibers to the temperature at which the polypropylene fibers soften and adhere to each other and also the rayon fibers and then cooling the resultant material. The second type of material used for floppy disk liners includes almost entirely polyester fibers. This type of fiber is formed into a cohesive layer by applying a liquid binder solution containing, in addition to other substances, polyester molecules and a catalyst, to a mass of loose fibers. This coated mass of fibers is then further processed to polymerize certain components in the binder solution yielding a cohesive layer of bound fibers comprising approximately 93% polyester fibers and 7% polyester terpolymer binder. The polyester terpolymer binder is formed by the polymerization of the polyester molecules contained in the binder solution applied to the loose fiber mass",
column 1, lines 31-34, the nonwoven cloth being one:
column 1, line 60-column 3, lines 8.
The '843 patent's disclosed improvement comprises including an anionic, cationic or nonionic antistatic agent in the nonwoven cloth to prevent it from becoming electrostatically charged; see, e.g., column 4, lines 21-30 and column 6, lines 42-50 of the '843 patent.
A diskette cartridge or envelope " . . . fabricated by bonding together a layer of porous fibrous, low-friction, anti-static material and a layer of solid material" is disclosed in U.S. Pat. No. 4,354,213, issued Oct. 12, 1982 to Martinelli; see column 1, lines 17-19. According to the '213 patent:
column 1, lines 24-51.
An overview of this technological area is given in Petkiewicz, "Nonwovens as Liners for Floppy Disks", Nonwovens World, May-June, 1986, pp. 120-124. The nonwoven fabric types identified by Petkiewicz as being used as floppy disk jacket liners are "thermally bonded rayon/polypropylene", "chemically bonded rayon/polyester (acrylic)", "chemically bonded rayon (SBR)" and "thermally bonded polyester"; Table 2, p. 123.
It is an object of this invention to provide novel diskette or disk jackets or cartridges and processes for their preparation.
Another object of this invention is to provide novel diskette or disk jackets or cartridges lined with particular nonwoven fabrics.
A further object of this invention is to provide an improved method of preparing diskette or disk jackets or cartridges lined with particular nonwoven fibers which achieves significant increases in production through-put rates for the blanks used to prepare diskette or disk jackets or cartridges as well as improvements in the lamination of the liner to the outer jacket material around cutouts in such jackets or cartridges.
These and other objects, as well as the nature, scope and utilization of this invention, will become readily apparent to those skilled in the art from the following description, the drawings and the appended claims.